Telecommunication and data switching systems are used to route tens of thousands of calls and data connections per second. The failure of such a system, due to either an equipment breakdown or a loss of power, is generally unacceptable since it would result in a loss of millions of voice and data communications along with its corresponding revenue. The traditionally high reliability of telecommunication systems, that users have come to expect, is partially based on the use of redundant equipment including power supplies.
Primary power is normally supplied through commercially available AC voltage. Should the AC voltage become unavailable due to an AC power outage or the failure of one or more of its associated components, a backup power capability supplies the needed voltages and currents to maintain operation of the system. This backup power capability can be provided by a battery plant, which generally includes a number of backup batteries as well as corresponding rectifying, inverting and associated power distribution equipment. The backup batteries provide power to the load in the event an AC power outage occurs. During normal operation, the backup batteries are usually maintained in a substantially fully-charged state to provide as long a duration for backup power as possible.
Multiple rectifier systems are connected to the battery plant's output bus to provide the needed load current by the telecommunication systems or other load equipment and maintain the battery charge, during these normal operating periods. These multiple rectifier systems may employ a disparate collection of rectifiers ranging from older embedded legacy rectifiers, whose output voltage and current values are not remotely controllable, to newly installed rectifiers that provide remote control capability of these functions.
The ability to determine how a load current will be shared between these multiple rectifier systems is an important consideration when loads are static. However, as loads become dynamic and the load current varies significantly, the question of how the load current is shared between multiple rectifier systems may become critical to efficient or even successful plant operation.
Older rectifier systems typically provide a manually-settable current share capability that accommodates load current sharing among only the older rectifier systems. Correspondingly, newer rectifier systems provide load current share capability among only the newer rectifier systems. However, the two types of rectifier systems do not provide a common current share, either by physical bus or otherwise, and are not currently able to actively current share. This is especially true when they are provided by different vendors.
Accordingly, what is needed in the art is a way to provide load current sharing between older and newer rectifier systems having differing load current share capabilities.